The size-uniformed mesoporous Ag@SiO
nanospheres' catalysts were prepared in one-pot step via reducing AgNO
by different types of aldehyde, which could control the size of Ag@SiO
NPs and exhibit ...excellent catalytic activity for the hydrogenation of nitrobenzene. The results showed that the Ag core size, monitored by different aldehydes with different reducing abilities, together with the ideal monodisperse core-shell mesoporous structure, was quite important to affect its superior catalytic performances. Moreover, the stability of Ag fixed in the core during reaction for 6 h under 2.0 MPa, 140 °C made this type of Ag@SiO
catalyst separable and environmentally friendly compared with those conventional homogeneous catalysts and metal NPs catalysts. The best catalyst with smaller Ag cores was prepared by strong reducing agents such as CH
O. The conversion of nitrobenzene can reach 99.9%, the selectivity was 100% and the catalyst maintained its activity after several cycles, and thus, it is a useful novel candidate for the production of aniline.
The size-uniformed mesoporous Ag@SiO2 nanospheres’ catalysts were prepared in one-pot step via reducing AgNO3 by different types of aldehyde, which could control the size of Ag@SiO2 NPs and exhibit ...excellent catalytic activity for the hydrogenation of nitrobenzene. The results showed that the Ag core size, monitored by different aldehydes with different reducing abilities, together with the ideal monodisperse core-shell mesoporous structure, was quite important to affect its superior catalytic performances. Moreover, the stability of Ag fixed in the core during reaction for 6 h under 2.0 MPa, 140 °C made this type of Ag@SiO2 catalyst separable and environmentally friendly compared with those conventional homogeneous catalysts and metal NPs catalysts. The best catalyst with smaller Ag cores was prepared by strong reducing agents such as CH2O. The conversion of nitrobenzene can reach 99.9%, the selectivity was 100% and the catalyst maintained its activity after several cycles, and thus, it is a useful novel candidate for the production of aniline.
We describe a navigation system based on Brooks'subsumption architecture. In the architecture, we use independent theorem proves to derive each layer's outputs given its inputs. We will show that how ...this architecture can give navigator such advantages as increased robustness, concurrency support, incremental construction and ease of testing. More importantly, it allows multiple goals to be serviced simultaneously and reactively. Finally, this paper presents the logic implementation of the system.
The loss of feeling is one of the biggest shortcomings in the traditional E-learning system. In order to compensate for this shortfall, we describe a face recognition-based Intelligent E-learning ...system based on Brooks' subsumption architecture. In this architecture, we implement the subsumption of lower layers by high layers using nonmonotonic reasoning principles. However, unlike systems that followed Brooks' work, it allows the layers to work in synergy to produce the compound behavior. Study shows that, based on the above structure, the system could track learners' emotional changes in real time, and dynamically adjust the learning strategies to make learners' study more efficient.
M-GBCP is a new topic in the field of e-GBCP, and regarded as the application of wireless communication technology and computer technology in the public management, which provides public service for ...the public through mobile terminal and network technology. This paper examines provision of public service based on mobile communications technology.
Uniaxial compression tests were conducted on four groups of coal samples under dry condition and 0, 3, and 5 MPa water immersion pressure using acoustic emission, scanning electron microscopy, and a ...digital scattered spot deformation monitoring system to investigate the mechanical properties and damage characteristics of coal samples under the action of water pressure. The results showed that as the water immersion pressure increased, the water-rock interaction intensified and aggravated the internal damage of the samples. The uniaxial compressive strength, elastic modulus, and peak strain decreased by 71.4%, 43.3%, and 34.74%, respectively. The deformation localized zone of the samples first appeared at the original crack in the deformation and failure process. As the water immersion pressure increased, the coal sample deformation localization zone appeared earlier, the displacement dislocation momentum of the deformation localization zone increased, and the deformation failure gradually increased, furthermore, the samples transitioned from brittle to plastic failure, and their failure mode changed from tensile to tensile-shear hybrid failure. The acoustic emission activity of the samples corresponds to their failure processes. The initial compaction stage of the samples was prolonged as the water immersion pressure increased. In the stage before the peak point, the plastic damage to the samples caused a gradual increase in the intensity and frequency of the acoustic emission signal, and multiple sudden increase points appeared. After the peak point, the active degree of the acoustic emission decreased, and the signal changed from "single tremors" to "swarm tremors" type fluctuation. The water immersion pressure promoted the water-rock interaction in the samples, the water flow continuously eroded the samples, and many water marks appeared on the fracture surface. The average porosity of the fracture surface increased, and the defect size of the coal samples increased.
Enhancer of zeste homolog 2 (EZH2)-mediated trimethylation of histone 3 lysine 27 (H3K27Me3) is critical for immune regulation. However, evidence is lacking to address the effect of EZH2 enzyme's ...activity on intestinal immune responses during inflammatory bowel disease (IBD). Here we report that suppressing EZH2 activity ameliorates experimental intestinal inflammation and delayed the onset of colitis-associated cancer. In addition, we identified an increased number of functional MDSCs in the colons, which are essential for EZH2 inhibitor activity. Moreover, inhibition of EZH2 activity promotes the generation of MDSCs from hematopoietic progenitor cells in vitro, demonstrating a previously unappreciated role for EZH2 in the development of MDSCs. Together, these findings suggest the feasibility of EZH2 inhibitor clinical trials for the control of IBD. In addition, this study identifies MDSC-promoting effects of EZH2 inhibitors that may be undesirable in other therapeutic contexts and should be addressed in a clinical trial setting.
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